Dental mandrel.



1 J M11 5 z 2 No. 7ll,340 Patented Oct. l4, I902.

G. J. PAYNTER,

DENTAL MANDBEL. (Application filed Apr. 2, 1902.)

(No Model.)

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THE NORRIS PETERS co. PHOTOVUTHD. wAsHmaYdu. o. c.

UNITED STATES PATENT ()FFICE.

GEORGE JANVIER PAYNTER, OF PHILADELPHIA, PENNSYLVANIA.

DENTAL MANDREL.

SPECIFICATION forming part of Letters Patent N 0. 711,340, dated October14, 1902.

Application filed April 2,1902.

To all, whom it may concern:

Beit known that I, GEORGE J ANVIER PAYN- TER, a citizen of the UnitedStates, residing at Philadelphia, in the county of Philadelphia andState ofPennsylvania, have invented certain new and useful Improvementsin Mandrels, of which the following is a specification. 7

My present invention pertains to improvements in mandrels, theconstruction and advantages of which will be hereinafter set forth,reference being bad to the annexed drawings, wherein- Figure 1 is aperspective view of the mandrel and disk to be held thereby, the partsbeing shown in their separated condition; Fig. 2, a side elevation,partly in section; Fig. 3, a vertical sectional view on the line 3 3 ofFig. 2; and Figs. 4 and 5, cross-sectional views on the lines 4 4 and 55, respectively.

The object of the present invention is the production of a mandrel whichmay be quickly and easily assembled and which when the parts arepositioned with the disk in place will securely hold the disk and causea posi tive rotation thereof irrespective of the direction of rotationof the mandrel. The posi tive rotation of the disk is of course ofmaterial advantage, and the present construction is also advantageous inthat the faster the mandrel is rotated the tighter the parts hold. Theconstruction is such that the disks will not slip off when subjected tothrust or pull.

Referring to the drawings, A denotes the spindle or stem of the mandrel,having one end enlarged, as at B, and formed with a circumferentialupstanding rim 0. The spindle is likewise provided with a central axialopening D and with a series of substantially V-shaped notches E, formedin the body, two of said notches being shown in the form illustrated.These notches are preferably arranged diametrically opposite and, aswill be seen upon reference to Figs. 1 and 3, are formed in line withlead-grooves F, the function of which will presently appear.

G denotes the head, preferably formed with a depending flange or rim Hand likewise provided with a stem or post I. Said head has two fingersor lugs J, extending down therefrom at or near its periphery, which areSerial No. 101,114. (No model.)

so positioned or arranged with reference to the notches E that they passinto said notches when the parts are assembled. As will be noted moreparticularly upon reference to Figs. 4 and 5, the fingers are V-shapedin cross-section, being complemental to the notches. This constructionproduces upon the ends of the fingers sharp or substantially sharppoints which readily puncture the disk K and yet leave no sharp pointorany projection whatsoever when the parts are assembled, the fingersthroughout lying flush with the body Band presenting an even smoothsurface.

In the act of securing a disk in place the stem or post I is passedthrough the central opening in the disk and into the opening D. The headis then pushed down, the fingers passing down through the disk and intothe notches E. Should the fingers, however,,not be in direct alinementwith the said notches, then the grooves F come into play, serving todirect the ends of the fingers into the notches E, giving the head aslight turn or rotation in so doing. portioned that the fingers fitsnugly into the notches E. In fact, the fingers may be said to be sprungoutwardly to a slight degree as they are forced down to place. The opp0-sitely-disposed rims O and H bind upon or bite into the disk slightly,thereby assisting the fingers in the secure holding of the disk.

As will be readily understood, the rotation of the mandrel causes whatmay be termeda setback of the disk and head, thereby causing the fingersto bind tightly onthe inclined faces of the notches, renderingseparation of the parts all the more difficult. The greater the rotationspeed the greater the centrifugal action and as a consequence thegreater the binding action between the parts. In practice with the diskat .Work the disk will drag back against the fingers, thereby causingthem to bind against the walls of the notches. This coupled with thecentrifugal action insures an eifectual clamping of the disk in place.

It is to be noted that there are no screws, springs, nuts, or the liketo become worn and loose and there is in addition to the diskitself, butone movable part-namely, the head. The disk may be quickly secured inplace or The parts are so proremoved by simply pushing the head to placeor removing the same. Moreover, the construction affords an even surfaceall over, free from any projections whatsoever.

together, substantially as described.

2. In a mandrel, the combination of a stem having a series ofsubstantially V shaped notches or grooves formed in the outer side facethereof at one end; and a removable head having doWnwardly-projectingfingers adapted to pass through a disk interposed between the head andstem, said fingers fitting within the notches or grooves, substantiallyas described.

3. In a mandrel, the combination of a stem; a removable head; andconnections between said head and stem having oppositely-inclinedbearing-faces, said faces lying in planes substantially parallel to theaxis of the stem whereby the greater the speed of revolution of themandrel the greater the frictional contact between the parts.

4. In a mandrel, the combination of a stem having a central axialopening, and a series of substantially V-shaped notches or grooves 5formed in the side face thereof at one end; a

head having downwardly-projecting fingers adapted to pass through a diskinterposed between the head and stem, said fingers fitting within thegrooves and being complemental in form to said grooves; and a postextending downwardly from said head and passing into the opening formedin the stem.

5. In a mandrel, the combination of a stem having an enlarged end, saidend being provided with a central axial opening and with substantiallyV-shaped notches or grooves in its outer face; an upstanding rim formedaround the periphery of said end; a head provided withdownwardly-projecting V-shaped fingers, said fingers fitting within thenotches or grooves formed in the enlarged end; acentral post extendingdownwardly from said head; and a depending rim or flange likewiseextending downwardly from said head, substantially as described.

V 6. In a mandrel, the combination of a stem having an enlarged end B,-said end being formed with an upstanding rim around its periphery andlikewise provided with V-shaped notches or grooves formed in its outerface, and a second series of grooves formed in its upper end in linewith the notches or grooves in the side; and a head provided withdownwardly-projecting fingers, a downwardly-projecting central postadapted and arranged to pass into an opening formed in the center of thestem, and likewise provided with a down-- wardly-projecting rim,substantially as and for the purpose described.

In testimony whereof I have signed my name to this specification in thepresence of two subscribing witnesses.

GEORGE .TANVIER PAYNTER.

Witnesses:

THEo. H. MOAnLA, HARRY BOSWELL.

